1. Field of the Invention
The present invention relates, in general, to a machine for picking up ties of a track while advancing continuously in an operating direction. The ties rest with their underside on a ballast bed.
2. Description of the Related Art
Our earlier U.S. Pat. No. 5,357,867 describes a machine of this type. The old ties which are to be removed in the course of a track renewal operation are lifted off the ballast bed by the tie pick-up device and stored intermediately on the machine. To that end, the tie is initially gathered up by the tie skids, then collected from there by way of a pivotable and vertically adjustable fork which lifts the tie and deposits it, with underside of the tie down, upon an engaging member of an endless transporting chain. The latter finally transports the tie to a tie transport unit positioned at an elevated location.
It is an object of the invention to provide a machine for picking up ties of a track that overcomes the disadvantages of the heretofore-known devices and methods of this general type and which provides for an improved machine that allows the tie picking-up operation to be carried out in a more efficient manner.
With the foregoing and other objects in view there is provided, in accordance with the invention, a machine for picking up ties of a track while advancing continuously in an operating direction, the ties having an underside resting on a ballast bed. The machine comprises a machine frame extending in a longitudinal direction; a tie transport unit arranged on the machine frame and having a receiving end; and a tie pick-up device associated with the tie transport unit. The tie pick-up device includes tie skids provided for permanent immersion in the ballast bed for support of the ties to be lifted, the tie skids being lengthened by a tie sliding track for supporting the underside of the ties, the tie sliding track extending substantially in the longitudinal direction and having a transfer end arranged in the region of the receiving end of the tie transport unit; and an endless transporting chain provided for shifting the ties from the ballast bed to the receiving end of the tie transport unit, the transporting chain comprising engaging members and having an upper and a lower deflection end which define a reference line disposed at an angle of less than 90xc2x0 with regard to the ballast bed, with the lower deflection end being positioned ahead of the upper deflection end in the operating direction
In accordance with an added feature of the invention, there is provided a tie pusher disposed in a region of the lower deflection end and above the tie skids, a first drive disposed to displace the tie pusher in the longitudinal direction relative to the lower deflection end and a second drive for pivoting the tie pusher about an axis extending perpendicularly to the longitudinal direction.
In accordance with an additional feature of the invention, a spacing distance between any two adjacent engaging members of the transporting chain is at least twice the given tie width.
In accordance with an additional feature of the invention, the tie skids are formed with a skid sliding surface enclosing an angle of between 130xc2x0 and 160xc2x0 with the tie sliding track.
In accordance with a concomitant feature of the invention, there is provided a deflection flap pivotally mounted at the transfer end of the tie sliding track about an axis extending perpendicularly to the longitudinal direction, for transferring a tie onto the tie transport unit.
A solution of this kind offers the advantage that the old tie to be removed is displaced in a sliding manner, starting from the tie skids all the way to the upper end of the tie pick-up device, thus rendering superfluous any efficiency-limiting transfer cycle of a single tie, such as described at the beginning. This structural solution also provides for a buffering possibility in the region of the tie skids on which, if necessary, even two immediately adjacent ties can be collected at the same time by the engaging member and displaced vertically without problems. Thus, in a particularly advantageous manner, even the presence of double ties, for example at a rail joint, does not lead to an impairment or reduction of the working performance and efficiency of the machine.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a machine for picking up ties of a track, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.